A043110 Numbers k such that 1 and 2 occur juxtaposed in the base-5 representation of k but not of k-1.

7, 11, 32, 35, 55, 61, 82, 86, 107, 111, 132, 136, 157, 160, 175, 207, 211, 232, 236, 257, 261, 275, 305, 311, 332, 336, 357, 361, 382, 386, 407, 410, 430, 436, 457, 461, 482, 486, 507, 511, 532, 535, 555, 561, 582, 586, 607, 611

Offset

1,1

Links

Table of n, a(n) for n=1..48.

Mathematica

SequencePosition[Table[If[SequenceCount[IntegerDigits[n, 5], {1, 2}]>0 || SequenceCount[IntegerDigits[n, 5], {2, 1}]>0, 1, 0], {n, 700}], {0, 1}][[All, 2]] (* Harvey P. Dale, Jan 14 2022 *)

Crossrefs

Cf. A007091.

Sequence in context: A084443 A228029 A053711 * A043890 A132355 A241573

Adjacent sequences: A043107 A043108 A043109 * A043111 A043112 A043113

Keyword

nonn,base

Author

Clark Kimberling

Status

approved